Heretofore, it was known that vitamin E can be dissolved in mixed micelles of cholanic acids and lecithins. However, these known solutions contained only small amounts of vitamin E. For example, in U.S. Pat. No. 3,197,368 there are described micelle solutions of lecithins and cholanic acids which can contain up to 2% of vitamin E (.alpha.-tocopherol) based on the amount of lecithin. In German Auslegeschrift No. 2,433,173 there are described micelle solutions of phospholipids and glycocholic acid which contain 10 mg of vitamin E and 5 g of phospholipid per liter of solution.
There exists a need to make available substantially more concentrated solutions of vitamin E which would be useful in the preparation of injectable solution.
It has now been found that more concentrated solutions of vitamin E than heretofore reported can be prepared by employing certain molar ratios of phospholipid and cholanic acid.